1 6140 62 THE ETIOLOGY OF AUTOIMMUNE DISEASES: THE CASE OF MYASTHENIA GRAVIS. AUTOIMMUNE DISEASES COMPRISE A WIDE VARIETY OF DISORDERS, FROM THOSE THAT ARE ACUTE AND SPONTANEOUSLY REGRESSIVE TO CHRONIC DISEASES. THEIR OCCURRENCE IS THE SIGN OF A LOSS OF TOLERANCE TO SELF-ANTIGENS. WITH FEW EXCEPTIONS, THE ETIOLOGY OF AUTOIMMUNE DISEASES HAS NOT BEEN CLEARLY ESTABLISHED. IN ALL CASES, IT IS COMPLEX, INVOLVING GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS. IN THIS ARTICLE I WILL ATTEMPT TO ANALYZE THE VARIOUS FACTORS THAT HAVE A TRIGGERING OR PROTECTING ROLE, WITH PARTICULAR REFERENCE TO MYASTHENIA GRAVIS. 2012 2 4975 27 PATHOPHYSIOLOGICAL MECHANISMS OF AUTOIMMUNITY. AUTOIMMUNE DISEASES (AIDS) ARE CHRONIC DISORDERS CHARACTERIZED BY INFLAMMATORY REACTIONS AGAINST SELF-ANTIGENS THAT CAN BE EITHER SYSTEMIC OR ORGAN SPECIFIC. AIDS CAN DIFFER IN THEIR EPIDEMIOLOGIC FEATURES AND CLINICAL PRESENTATIONS, YET ALL SHARE A REMARKABLE COMPLEXITY. AIDS RESULT FROM AN INTERPLAY OF GENETIC AND EPIGENETIC FACTORS WITH ENVIRONMENTAL COMPONENTS THAT ARE ASSOCIATED WITH IMBALANCES IN THE IMMUNE SYSTEM. MANY OF THE PATHOGENIC MECHANISMS OF AIDS ARE ALSO IMPLICATED IN MYASTHENIA GRAVIS (MG), AN AID IN WHICH INFLAMMATION OF THE THYMUS LEADS TO A NEUROMUSCULAR DISORDER. OUR GOAL HERE IS TO HIGHLIGHT THE SIMILARITIES AND DIFFERENCES BETWEEN MG AND OTHER AIDS BY REVIEWING THE COMMON TRANSCRIPTOME SIGNATURES AND THE DEVELOPMENT OF GERMINAL CENTERS AND BY DISCUSSING SOME UNRESOLVED QUESTIONS ABOUT AUTOIMMUNE MECHANISMS. THIS REVIEW WILL PROPOSE HYPOTHESES TO EXPLAIN THE ORIGIN OF REGULATORY T (T(REG) ) CELL DEFECTS AND THE CAUSES OF CHRONICITY AND SPECIFICITY OF AIDS. 2018 3 6345 29 THE ROLE OF EPIGENETICS IN AUTOIMMUNE/INFLAMMATORY DISEASE. HISTORICALLY, SYSTEMIC SELF-INFLAMMATORY CONDITIONS WERE CLASSIFIED AS EITHER AUTOINFLAMMATORY AND CAUSED BY THE INNATE IMMUNE SYSTEM OR AUTOIMMUNE AND DRIVEN BY ADAPTIVE IMMUNE RESPONSES. HOWEVER, IT BECAME CLEAR THAT REALITY IS MUCH MORE COMPLEX AND THAT AUTOIMMUNE/INFLAMMATORY CONDITIONS RANGE ALONG AN "INFLAMMATORY SPECTRUM" WITH PRIMARILY AUTOINFLAMMATORY VS. AUTOIMMUNE CONDITIONS RESEMBLING EXTREMES AT EITHER END. EPIGENETIC MODIFICATIONS INFLUENCE GENE EXPRESSION AND ALTER CELLULAR FUNCTIONS WITHOUT MODIFYING THE GENOMIC SEQUENCE. METHYLATION OF CPG DNA DINUCLEOTIDES AND/OR THEIR HYDROXYMETHYLATION, POST-TRANSLATIONAL MODIFICATIONS TO AMINO TERMINI OF HISTONE PROTEINS, AND NON-CODING RNA EXPRESSION ARE MAIN EPIGENETIC EVENTS. THE PATHOPHYSIOLOGY OF AUTOIMMUNE/INFLAMMATORY DISEASES HAS BEEN CLOSELY LINKED WITH DISEASE CAUSING GENE MUTATIONS (RARE) OR A COMBINATION OF GENETIC SUSCEPTIBILITY AND EPIGENETIC MODIFICATIONS ARISING FROM EXPOSURE TO THE ENVIRONMENT (MORE COMMON). OVER RECENT YEARS, PROGRESS HAS BEEN MADE IN UNDERSTANDING MOLECULAR MECHANISMS INVOLVED IN SYSTEMIC INFLAMMATION AND THE CONTRIBUTION OF INNATE AND ADAPTIVE IMMUNE RESPONSES. EPIGENETIC EVENTS HAVE BEEN IDENTIFIED AS (I) CENTRAL PATHOPHYSIOLOGICAL FACTORS IN ADDITION TO GENETIC DISEASE PREDISPOSITION AND (II) AS CO-FACTORS DETERMINING CLINICAL PICTURES AND OUTCOMES IN INDIVIDUALS WITH MONOGENIC DISEASE. THUS, A COMPLETE UNDERSTANDING OF EPIGENETIC CONTRIBUTORS TO AUTOIMMUNE/INFLAMMATORY DISEASE WILL RESULT IN APPROACHES TO PREDICT INDIVIDUAL DISEASE OUTCOMES AND THE INTRODUCTION OF EFFECTIVE, TARGET-DIRECTED, AND TOLERABLE THERAPIES. HERE, WE SUMMARIZE RECENT FINDINGS THAT SIGNIFY THE IMPORTANCE OF EPIGENETIC MODIFICATIONS IN AUTOIMMUNE/INFLAMMATORY DISORDERS ALONG THE INFLAMMATORY SPECTRUM CHOOSING THREE EXAMPLES: THE AUTOINFLAMMATORY BONE CONDITION CHRONIC NONBACTERIAL OSTEOMYELITIS (CNO), THE "MIXED PATTERN" DISORDER PSORIASIS, AND THE AUTOIMMUNE DISEASE SYSTEMIC LUPUS ERYTHEMATOSUS (SLE). 2019 4 2529 25 EPIGENETICS CHANGES ASSOCIATED TO ENVIRONMENTAL TRIGGERS IN AUTOIMMUNITY. AUTOIMMUNE DISEASES (AIDS) ARE CHRONIC CONDITIONS INITIATED BY THE LOSS OF IMMUNOLOGICAL TOLERANCE TO SELF-ANTIGENS AND REPRESENT A HETEROGENEOUS GROUP OF DISORDERS THAT AFFECT SPECIFIC TARGET ORGANS OR MULTIPLE ORGANS IN DIFFERENT SYSTEMS. WHILE THE PATHOGENESIS OF AID REMAINS UNCLEAR, ITS AETIOLOGY IS MULTIFUNCTIONAL AND INCLUDES A COMBINATION OF GENETIC, EPIGENETIC, IMMUNOLOGICAL AND ENVIRONMENTAL FACTORS. IN AIDS, SEVERAL EPIGENETIC MECHANISMS ARE DEFECTIVE INCLUDING DNA DEMETHYLATION, ABNORMAL CHROMATIN POSITIONING ASSOCIATED WITH AUTOANTIBODY PRODUCTION AND ABNORMALITIES IN THE EXPRESSION OF RNA INTERFERENCE (RNAI). IT IS KNOWN THAT ENVIRONMENTAL FACTORS MAY INTERFERE WITH DNA METHYLATION AND HISTONE MODIFICATIONS, HOWEVER, LITTLE IS KNOWN ABOUT EPIGENETIC CHANGES DERIVED OF REGULATION OF RNAI. AN APPROACH TO THE KNOWN ENVIRONMENTAL FACTORS AND THE MECHANISMS THAT ALTER THE EPIGENETIC REGULATION IN AIDS (WITH EMPHASIS IN SYSTEMIC LUPUS ERYTHEMATOSUS, THE PROTOTYPE OF SYSTEMIC AID) ARE SHOWED IN THIS REVIEW. 2016 5 6791 21 [DOES THE NUMBER OF PATIENTS WITH AUTOIMMUNE DISORDERS AND THE FREQUENCY OF AUTOIMMUNE DISEASES INCREASE?]. AUTOIMMUNE DISEASES GENERALLY BELONG TO THE RARE DISEASES, HOWEVER, SOME OF THEM ARE FREQUENT IN THE POPULATION. IN THE PRESENT WORK THE AUTHORS ANALYSE WHETHER CAN ANY INCREASE BE OBSERVED IN THE NUMBER OF PATIENTS SUFFERING FROM AUTOIMMUNE DISEASES AND WHETHER DO THE FREQUENCY OF CERTAIN AUTOIMMUNE DISORDERS INCREASE. DUE MAINLY TO EPIGENETIC FACTORS THE INCIDENCE OF AUTOIMMUNE DISEASES ARE INCREASING, THEREFORE THERE ARE MORE PATIENTS RECOGNISED WITH PARTICULAR DISORDERS. ON THE OTHER HAND THE INCIDENCE IS INCREASED BY IMPROVING DIAGNOSTIC POSSIBILITIES, BY THE USE OF MORE SPECIFIC AND SENSITIVE CLASSIFICATION CRITERIA AND MORE SOPHISTICATED LABORATORY TESTS, RESULTED IN THE RECOGNITION OF MILDER AND ATYPICAL DISEASE VARIANTS AS WELL. THE PREVALENCE IS ALSO INCREASING IN CONSEQUENCE OF NOVEL IMMUNE SUPPRESSIVE THERAPEUTIC POSSIBILITIES AND THE CONSEQUENT IMPROVEMENT OF SURVIVAL IN THE MOST OF THESE DISEASES. BESIDES, MORE AND MORE DISEASES HAVE BEEN REVEALED TO HAVE AUTOIMMUNE BACKGROUND, AND LOT OF NEW AUTOIMMUNE SYNDROMES, DISEASES HAVE BEEN CHARACTERISED RECENTLY. THIS INCREASES THE NUMBER OF THE KNOWN AUTOIMMUNE RHEUMATIC DISORDERS WITH A CONSEQUENT INCREASE IN THE NUMBER OF AUTOIMMUNE PATIENTS. ASSIGNED TO THE INCREASING NUMBER OF VARIABLE CHRONIC AUTOIMMUNE DISORDERS, AND THE INCREASING NUMBER OF DISABLED PATIENTS WITH SUCH DISEASES INCREASING MEDICAL AND SOCIAL ATTENTION HAS TO BE FOCUSED ON. 2007 6 549 22 AUTOANTIGENS: NOVEL FORMS AND PRESENTATION TO THE IMMUNE SYSTEM. IT IS CLEAR THAT LUPUS AUTOIMMUNITY IS MARKED BY A VARIETY OF ABNORMALITIES, INCLUDING THOSE FOUND AT A MACROSCOPIC SCALE, CELLS AND TISSUES, AS WELL AS MORE MICROENVIRONMENTAL INFLUENCES, ORIGINATING AT THE INDIVIDUAL CELL SURFACE THROUGH TO THE NUCLEUS. THE CONVERGENCE OF GENETIC, EPIGENETIC, AND PERHAPS ENVIRONMENTAL INFLUENCES ALL LEAD TO THE OVERT CLINICAL EXPRESSION OF DISEASE, REFLECTED BY THE PRESENCES OF AUTOANTIBODIES AND TISSUE PATHOLOGY. THIS REVIEW WILL ADDRESS SEVERAL SPECIFIC AREAS THAT FALL AMONG THE NON-GENETIC FACTORS THAT CONTRIBUTE TO LUPUS AUTOIMMUNITY AND RELATED SYNDROMES. IN PARTICULAR, WE WILL DISCUSS THE IMPORTANCE OF UNDERSTANDING VARIOUS PROTEIN POST-TRANSLATIONAL MODIFICATIONS (PTMS), MECHANISMS THAT MEDIATE THE ABILITY OF "MODIFIED SELF" TO TRIGGER AUTOIMMUNITY, AND HOW THESE PTMS INFLUENCE LUPUS DIAGNOSIS. FINALLY, WE WILL DISCUSS ALTERED PATHWAYS OF AUTOANTIGEN PRESENTATION THAT MAY CONTRIBUTE TO THE PERPETUATION OF CHRONIC AUTOIMMUNE DISEASE. 2014 7 3016 25 GENETICS AND EPIGENETICS OF IBD. INFLAMMATORY BOWEL DISEASES (IBD) ARE CHRONIC INTERMITTENT INFLAMMATORY DISORDERS OF THE GASTROINTESTINAL TRACT OF UNKNOWN ETIOLOGY BUT A CLEAR GENETIC PREDISPOSITION. PROMPTED BY THE FIRST INVESTIGATIONS ON IBD FAMILIES AND TWINS, THE GENETIC AND EPIGENETIC STUDIES HAVE PRODUCED AN UNPRECEDENTED AMOUNT OF INFORMATION IN COMPARISON WITH OTHER IMMUNE-MEDIATED OR COMPLEX DISEASES. NEW INFLAMMATORY PATHWAYS AND POSSIBLE MECHANISMS OF ACTION HAVE BEEN DISCLOSED, POTENTIALLY LEADING TO NEW-TARGETED THERAPY. HOWEVER, THE IDENTIFICATION OF GENETIC MARKERS DUE TO THE GREAT DISEASE HETEROGENEITY AND THE OVERWHELMING CONTRIBUTION OF ENVIRONMENTAL RISK FACTORS HAS NOT MODIFIED YET THE DISEASE MANAGEMENT. THE POSSIBILITY FOR THE FUTURE OF A BETTER PREDICTION OF DISEASE COURSE, RESPONSE TO THERAPY AND THERAPY-RELATED ADVERSE EVENTS MAY ALLOW A MORE EFFICIENT AND PERSONALIZED STRATEGY. THIS REVIEW WILL FOCUS ON MORE RECENT DISCOVERIES THAT MAY POTENTIALLY BE OF RELEVANCE IN DAILY CLINICAL PRACTICE. 2020 8 6276 23 THE PATHOGENIC ROLE OF DYSREGULATED EPIGENETIC MODIFICATIONS IN AUTOIMMUNE DISEASES. AUTOIMMUNE DISEASES CAN BE CHRONIC WITH RELAPSE OF INFLAMMATORY SYMPTOMS, BUT IT CAN BE ALSO ACUTE AND LIFE-THREATENING IF IMMUNE CELLS DESTROY LIFE-SUPPORTING ORGANS, SUCH AS LUPUS NEPHRITIS. THE ETIOPATHOGENESIS OF AUTOIMMUNE DISEASES HAS BEEN REVEALED AS THAT GENETICS AND ENVIRONMENTAL FACTORS-MEDIATED DYSREGULATED IMMUNE RESPONSES CONTRIBUTE TO THE INITIATION AND DEVELOPMENT OF AUTOIMMUNE DISORDERS. HOWEVER, THE CURRENT UNDERSTANDING OF PATHOGENESIS IS LIMITED AND THE UNDERLYING MECHANISM HAS NOT BEEN WELL DEFINED, WHICH LOWS THE DEVELOPMENT OF NOVEL BIOMARKERS AND NEW THERAPEUTIC STRATEGIES FOR AUTOIMMUNE DISEASES. TO IMPROVE THIS, BROADENING AND DEEPENING OUR UNDERSTANDING OF PATHOGENESIS IS AN UNMET NEED. AS GENETIC SUSCEPTIBILITY CANNOT EXPLAIN THE LOW ACCORDANCE RATE OF INCIDENCE IN HOMOZYGOUS TWINS, EPIGENETIC REGULATIONS MIGHT BE AN ADDITIONAL EXPLANATION. THEREFORE, THIS REVIEW WILL SUMMARIZE CURRENT PROGRESS OF STUDIES ON EPIGENETIC DYSREGULATIONS CONTRIBUTING TO AUTOIMMUNE DISEASES, INCLUDING SLE, RHEUMATOID ARTHRITIS (RA), PSORIASIS, TYPE 1 DIABETES (T1D), AND SYSTEMIC SCLEROSIS (SSC), HOPEFULLY PROVIDING OPINIONS ON ORIENTATION OF FUTURE RESEARCH, AS WELL AS DISCUSSING THE CLINICAL UTILIZATION OF POTENTIAL BIOMARKERS AND THERAPEUTIC STRATEGIES FOR THESE DISEASES. 2019 9 2027 23 EPIGENETIC CHANGES IN CHRONIC INFLAMMATORY DISEASES. THE NUMBER OF PEOPLE DIAGNOSED WITH CHRONIC INFLAMMATORY DISEASES HAS INCREASED NOTEWORTHY IN THE LAST 40 YEARS. SPONDYLOARTHRITIS (SPA), INFLAMMATORY BOWEL DISEASES (IBD), AND PSORIASIS ARE THE MOST FREQUENT CHRONIC INFLAMMATORY DISEASES, RESULTING FROM A COMBINATION OF GENETIC PREDISPOSITION AND ENVIRONMENTAL FACTORS. EPIGENETIC MODIFICATIONS INCLUDE DNA METHYLATION, HISTONE MODIFICATIONS, AND SMALL AND LONG NONCODING RNAS. THEY ARE INFLUENCED BY ENVIRONMENTAL EXPOSURE, LIFE-STYLE, AND AGING AND HAVE RECENTLY BEEN SHOWN TO BE ALTERED IN MANY COMPLEX DISEASES INCLUDING INFLAMMATORY DISEASES. WHILE EPIGENETIC MODIFICATIONS HAVE BEEN WELL CHARACTERIZED IN OTHER DISEASES SUCH AS CANCER AND AUTOIMMUNE DISEASES, KNOWLEDGE ON CHANGES IN INFLAMMATORY DISEASES IS LAGGING BEHIND WITH SOME DISEASE-SPECIFIC DIFFERENCES. WHILE THE DNA METHYLATION PROFILE OF DIFFERENT CELL TYPES IN PATIENTS WITH IBD HAS BEEN RELATIVELY WELL DESCRIBED, LESS IS KNOWN ON CHANGES IMPLICATED IN PSORIASIS, AND NO SYSTEMATIC GENOME-WIDE STUDIES HAVE SO FAR BEEN PERFORMED IN SPA. IN THIS CHAPTER, WE REVIEW IN DETAIL THE REPORTED CHANGES IN PATTERNS OF DNA METHYLATION AND POSTTRANSLATIONAL HISTONE MODIFICATIONS IN CHRONIC INFLAMMATORY DISEASES HIGHLIGHTING POTENTIAL CONNECTIONS BETWEEN DISEASE-ASSOCIATED PATHOPHYSIOLOGICAL CHANGES SUCH AS THE DYSBIOSIS OF THE MICROBIOME OR GENETIC VARIATIONS ASSOCIATED WITH DISEASE SUSCEPTIBILITY AND THE EPIGENOME. WE ALSO DISCUSS IMPORTANT PARAMETERS OF MEANINGFUL EPIGENETIC STUDIES SUCH AS THE USE OF WELL DEFINED, DISEASE-RELEVANT CELL POPULATIONS, AND ELUDE ON THE POTENTIAL FUTURE OF ENGINEERING OF THE EPIGENOME IN INFLAMMATORY DISEASES. 2017 10 6178 20 THE HISTONE MODIFICATION CODE IN THE PATHOGENESIS OF AUTOIMMUNE DISEASES. AUTOIMMUNE DISEASES ARE CHRONIC INFLAMMATORY DISORDERS CAUSED BY A LOSS OF SELF-TOLERANCE, WHICH IS CHARACTERIZED BY THE APPEARANCE OF AUTOANTIBODIES AND/OR AUTOREACTIVE LYMPHOCYTES AND THE IMPAIRED SUPPRESSIVE FUNCTION OF REGULATORY T CELLS. THE PATHOGENESIS OF AUTOIMMUNE DISEASES IS EXTREMELY COMPLEX AND REMAINS LARGELY UNKNOWN. RECENT ADVANCES INDICATE THAT ENVIRONMENTAL FACTORS TRIGGER AUTOIMMUNE DISEASES IN GENETICALLY PREDISPOSED INDIVIDUALS. IN ADDITION, ACCUMULATING RESULTS HAVE INDICATED A POTENTIAL ROLE OF EPIGENETIC MECHANISMS, SUCH AS HISTONE MODIFICATIONS, IN THE DEVELOPMENT OF AUTOIMMUNE DISEASES. HISTONE MODIFICATIONS REGULATE THE CHROMATIN STATES AND GENE TRANSCRIPTION WITHOUT ANY CHANGE IN THE DNA SEQUENCE, POSSIBLY RESULTING IN PHENOTYPE ALTERATION IN SEVERAL DIFFERENT CELL TYPES. IN THIS PAPER, WE DISCUSS THE SIGNIFICANT ROLES OF HISTONE MODIFICATIONS INVOLVED IN THE PATHOGENESIS OF AUTOIMMUNE DISEASES, INCLUDING RHEUMATOID ARTHRITIS, SYSTEMIC LUPUS ERYTHEMATOSUS, SYSTEMIC SCLEROSIS, PRIMARY BILIARY CIRRHOSIS, AND TYPE 1 DIABETES. 2017 11 6288 29 THE POTENTIAL ROLE OF EPIGENETIC MODIFICATIONS ON DIFFERENT FACETS IN THE PERIODONTAL PATHOGENESIS. PERIODONTITIS IS A CHRONIC INFLAMMATORY DISEASE THAT AFFECTS THE SUPPORTING STRUCTURES OF TEETH. IN THE LITERATURE, THE ASSOCIATION BETWEEN THE PATHOGENICITY OF BACTERIA AND ENVIRONMENTAL FACTORS IN THIS REGARD HAVE BEEN EXTENSIVELY EXAMINED. IN THE PRESENT STUDY, WE WILL SHED LIGHT ON THE POTENTIAL ROLE THAT EPIGENETIC CHANGE CAN PLAY ON DIFFERENT FACETS OF ITS PROCESS, MORE PARTICULARLY THE MODIFICATIONS CONCERNING THE GENES INVOLVED IN INFLAMMATION, DEFENSE, AND IMMUNE SYSTEMS. SINCE THE 1960S, THE ROLE OF GENETIC VARIANTS IN THE ONSET AND SEVERITY OF PERIODONTAL DISEASE HAS BEEN WIDELY DEMONSTRATED. THESE MAKE SOME PEOPLE MORE SUSCEPTIBLE TO DEVELOPING IT THAN OTHERS. IT HAS BEEN DOCUMENTED THAT THE WIDE VARIATION IN ITS FREQUENCY FOR VARIOUS RACIAL AND ETHNIC POPULATIONS IS DUE PRIMARILY TO THE COMPLEX INTERPLAY AMONG GENETIC FACTORS WITH THOSE AFFECTING THE ENVIRONMENT AND THE DEMOGRAPHY. IN MOLECULAR BIOLOGY, EPIGENETIC MODIFICATIONS ARE DEFINED AS ANY CHANGE IN THE PROMOTER FOR THE CPG ISLANDS, IN THE STRUCTURE OF THE HISTONE PROTEIN, AS WELL AS POST-TRANSLATIONAL REGULATION BY MICRORNAS (MIRNAS), BEING KNOWN TO CONTRIBUTE TO THE ALTERATION IN GENE EXPRESSION FOR COMPLEX MULTIFACTORIAL DISEASES SUCH AS PERIODONTITIS. THE KEY ROLE OF EPIGENETIC MODIFICATION IS TO UNDERSTAND THE MECHANISM INVOLVED IN THE GENE-ENVIRONMENT INTERACTION, AND THE DEVELOPMENT OF PERIODONTITIS IS NOW THE SUBJECT OF MORE AND MORE STUDIES THAT ATTEMPT TO IDENTIFY WHICH FACTORS ARE STIMULATING IT, BUT ALSO AFFECT THE REDUCED RESPONSE TO THERAPY. 2023 12 6194 21 THE IMPACT OF PROTEIN ACETYLATION/DEACETYLATION ON SYSTEMIC LUPUS ERYTHEMATOSUS. SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE IN WHICH THE BODY'S IMMUNE SYSTEM MISTAKENLY ATTACKS HEALTHY CELLS. ALTHOUGH THE EXACT CAUSE OF SLE HAS NOT BEEN IDENTIFIED, IT IS CLEAR THAT BOTH GENETICS AND ENVIRONMENTAL FACTORS TRIGGER THE DISEASE. IDENTICAL TWINS HAVE A 24% CHANCE OF GETTING LUPUS DISEASE IF THE OTHER ONE IS AFFECTED. INTERNAL FACTORS SUCH AS FEMALE GENDER AND SEX HORMONES, THE MAJOR HISTOCOMPATIBILITY COMPLEX (MHC) LOCUS AND OTHER GENETIC POLYMORPHISMS HAVE BEEN SHOWN TO AFFECT SLE, AS WELL AS EXTERNAL, ENVIRONMENTAL INFLUENCES SUCH AS SUNLIGHT EXPOSURE, SMOKING, VITAMIN D DEFICIENCY, AND CERTAIN INFECTIONS. SEVERAL STUDIES HAVE REPORTED AND PROPOSED MULTIPLE ASSOCIATIONS BETWEEN THE ALTERATION OF THE EPIGENOME AND THE PATHOGENESIS OF AUTOIMMUNE DISEASE. EPIGENETIC FACTORS CONTRIBUTING TO SLE INCLUDE MICRORNAS, DNA METHYLATION STATUS, AND THE ACETYLATION/DEACETYLATION OF HISTONE PROTEINS. ADDITIONALLY, THE ACETYLATION OF NON-HISTONE PROTEINS CAN ALSO INFLUENCE CELLULAR FUNCTION. A BETTER UNDERSTANDING OF NON-GENOMIC FACTORS THAT REGULATE SLE WILL PROVIDE INSIGHT INTO THE MECHANISMS THAT INITIATE AND FACILITATE DISEASE AND ALSO CONTRIBUTE TO THE DEVELOPMENT OF NOVEL THERAPEUTICS THAT CAN SPECIFICALLY TARGET PATHOGENIC MOLECULAR PATHWAYS. 2018 13 1933 23 ENVIRONMENTAL FACTORS ASSOCIATED WITH TYPE 1 DIABETES. TYPE 1 DIABETES (T1D) IS A CHRONIC AUTOIMMUNE DISORDER THAT LEADS TO PROGRESSIVE PANCREATIC SS-CELL DESTRUCTION AND CULMINATES IN ABSOLUTE INSULIN DEFICIENCY AND STABLE HYPERGLYCAEMIA. IT IS VERY LIKELY THAT ENVIRONMENTAL FACTORS PLAY A ROLE IN TRIGGERING ISLET AUTOIMMUNITY. KNOWING WHETHER THEY HAVE TRUE RELEVANCE IN FAVORING T1D DEVELOPMENT IS ESSENTIAL FOR THE EFFECTIVE PREVENTION OF THE DISEASE. MOREOVER, PREVENTION COULD BE OBTAINED DIRECTLY INTERFERING WITH THE DEVELOPMENT OF AUTOIMMUNITY THROUGH AUTOANTIGEN-BASED IMMUNOTHERAPY. IN THIS NARRATIVE REVIEW, THE PRESENT POSSIBILITIES FOR THE PREVENTION OF T1D ARE DISCUSSED. PRESENTLY, INTERVENTIONS TO PREVENT T1D ARE GENERALLY MADE IN SUBJECTS IN WHOM AUTOIMMUNITY IS ALREADY ACTIVATED AND AUTOANTIBODIES AGAINST PANCREATIC CELL COMPONENTS HAVE BEEN DETECTED. PRACTICALLY, THE GOAL IS TO SLOW DOWN THE IMMUNE PROCESS BY PRESERVING THE NORMAL STRUCTURE OF THE PANCREATIC ISLETS FOR AS LONG AS POSSIBLE. UNFORTUNATELY, PRESENTLY METHODS ABLE TO AVOID THE RISK OF AUTOIMMUNE ACTIVATION ARE NOT AVAILABLE. ELIMINATION OF ENVIRONMENTAL FACTORS ASSOCIATED WITH T1D DEVELOPMENT, REVERSE OF EPIGENETIC MODIFICATIONS THAT FAVOR INITIATION OF AUTOIMMUNITY IN SUBJECTS EXPOSED TO ENVIRONMENTAL FACTORS AND USE OF AUTOANTIGEN-BASED IMMUNOTHERAPY ARE POSSIBLE APPROACHES, ALTHOUGH FOR ALL THESE MEASURES DEFINITIVE CONCLUSIONS CANNOT BE DRAWN. HOWEVER, THE ROAD IS TRACED AND IT IS POSSIBLE THAT IN A NOT SO DISTANT FUTURE AN EFFECTIVE PREVENTION OF THE DISEASE TO ALL THE SUBJECTS AT RISK CAN BE OFFERED. 2019 14 6344 20 THE ROLE OF EPIGENETICS IN AGING AND AUTOIMMUNITY. THE DECLINE IN IMMUNOCOMPETENCE WITH AGE IS ACCOMPANIED BY THE INCREASE IN THE INCIDENCE OF AUTOIMMUNE DISEASES. AGING OF THE IMMUNE SYSTEM, OR IMMUNOSENESCENCE, IS CHARACTERIZED BY A DECLINE OF BOTH T AND B CELL FUNCTION, AND PARADOXICALLY THE PRESENCE OF LOW-GRADE CHRONIC INFLAMMATION. THERE IS GROWING EVIDENCE THAT EPIGENETICS, THE STUDY OF INHERITED CHANGES IN GENE EXPRESSION THAT ARE NOT ENCODED BY THE DNA SEQUENCE ITSELF, CHANGES WITH AGING. INTERESTINGLY, EMERGING EVIDENCE SUGGESTS A KEY ROLE FOR EPIGENETICS IN HUMAN PATHOLOGIES, INCLUDING INFLAMMATORY AND NEOPLASTIC DISORDERS. HERE, WE WILL REVIEW THE POTENTIAL MECHANISMS THAT CONTRIBUTE TO THE INCREASE IN AUTOIMMUNE RESPONSES IN AGING. IN PARTICULAR, WE WILL DISCUSS HOW EPIGENETIC ALTERATIONS, ESPECIALLY DNA METHYLATION AND HISTONE ACETYLATION, ARE ACCUMULATED DURING AGING AND HOW THESE EVENTS CONTRIBUTE TO AUTOIMMUNITY RISK. 2010 15 398 22 AN UPDATE ON GENETIC SUSCEPTIBILITY IN LUPUS NEPHRITIS. SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) IS A CHRONIC AUTOIMMUNE DISEASE CHARACTERIZED BY MULTIPLE SYSTEM INVOLVEMENT AND POSITIVE SERUM AUTOANTIBODIES. LUPUS NEPHRITIS (LN) IS THE MOST COMMON AND SERIOUS COMPLICATION OF SLE, AND IT IS THE MAIN CAUSE OF DEATH IN PATIENTS WITH SLE. ABNORMALITIES IN THE IMMUNE SYSTEM LEAD TO LN AND INVOLVE A VARIETY OF CELLS (T CELLS, B CELLS, MACROPHAGES, NK CELLS, ETC.), CYTOKINES (INTERLEUKIN, TUMOR NECROSIS FACTOR ALPHA, ETC.) AND THEIR RELATED PATHWAYS. PREVIOUS STUDIES HAVE SHOWN THAT THE INTERACTIONS OF GENETIC, EPIGENETIC AND ENVIRONMENTAL FACTORS CONTRIBUTE TO THE PATHOGENESIS AND DEVELOPMENT OF LN. IN RECENT YEARS, ONE GENOME-WIDE ASSOCIATION STUDY (GWAS) AND A NUMBER OF GENE ASSOCIATION STUDIES HAVE EXPLORED THE SUSCEPTIBILITY GENES OF LN, INCLUDING IMMUNIZATION-, INFLAMMATION-, ADHESION- AND OTHER PATHWAY-RELATED GENES. THESE GENES PARTICIPATE IN OR SUGGEST THE PATHOGENESIS AND PROGRESSION OF LN. IN THIS REVIEW, WE SUMMARIZE THE GENETIC SUSCEPTIBILITY OF LN AND DISCUSS THE POSSIBLE MECHANISM UNDERLYING THE SUSCEPTIBILITY GENES OF LN. 2020 16 1463 24 DISSECTING COMPLEX EPIGENETIC ALTERATIONS IN HUMAN LUPUS. SYSTEMIC LUPUS ERYTHEMATOSUS IS A CHRONIC RELAPSING AUTOIMMUNE DISEASE THAT PRIMARILY AFFLICTS WOMEN, AND BOTH A GENETIC PREDISPOSITION AND APPROPRIATE ENVIRONMENTAL EXPOSURES ARE REQUIRED FOR LUPUS TO DEVELOP AND FLARE. THE GENETIC REQUIREMENT IS EVIDENCED BY AN INCREASED CONCORDANCE IN IDENTICAL TWINS AND BY THE VALIDATION OF AT LEAST 35 SINGLE-NUCLEOTIDE POLYMORPHISMS PREDISPOSING PATIENTS TO LUPUS. GENES ALONE, THOUGH, ARE NOT ENOUGH. THE CONCORDANCE OF LUPUS IN IDENTICAL TWINS IS OFTEN INCOMPLETE, AND WHEN CONCORDANT, THE AGE OF ONSET IS USUALLY DIFFERENT. LUPUS IS ALSO NOT PRESENT AT BIRTH, BUT ONCE THE DISEASE DEVELOPS, IT TYPICALLY FOLLOWS A CHRONIC RELAPSING COURSE. THUS, GENES ALONE ARE INSUFFICIENT TO CAUSE HUMAN LUPUS, AND ADDITIONAL FACTORS ENCOUNTERED IN THE ENVIRONMENT AND OVER TIME ARE REQUIRED TO INITIATE THE DISEASE AND SUBSEQUENT FLARES. THE NATURE OF THE ENVIRONMENTAL CONTRIBUTION, THOUGH, AND THE MECHANISMS BY WHICH ENVIRONMENTAL AGENTS MODIFY THE IMMUNE RESPONSE TO CAUSE LUPUS ONSET AND FLARES IN GENETICALLY PREDISPOSED PEOPLE HAVE BEEN CONTROVERSIAL. REPORTS THAT THE LUPUS-INDUCING DRUGS PROCAINAMIDE AND HYDRALAZINE ARE EPIGENETIC MODIFIERS, THAT EPIGENETICALLY MODIFIED T CELLS ARE SUFFICIENT TO CAUSE LUPUS-LIKE AUTOIMMUNITY IN ANIMAL MODELS, AND THAT PATIENTS WITH ACTIVE LUPUS HAVE EPIGENETIC CHANGES SIMILAR TO THOSE CAUSED BY PROCAINAMIDE AND HYDRALAZINE HAVE PROMPTED A GROWING INTEREST IN HOW EPIGENETIC ALTERATIONS CONTRIBUTE TO THIS DISEASE. UNDERSTANDING HOW EPIGENETIC MECHANISMS MODIFY T CELLS TO CONTRIBUTE TO LUPUS REQUIRES AN UNDERSTANDING OF HOW EPIGENETIC MECHANISMS REGULATE GENE EXPRESSION. THE ROLES OF DNA METHYLATION, HISTONE MODIFICATIONS, AND MICRORNAS IN LUPUS PATHOGENESIS WILL BE REVIEWED HERE. 2013 17 6821 27 [GASTROINTESTINAL MANIFESTATIONS IN IMMUNODEFICIENCIES WITH MONOGENIC ORIGIN]. ALTHOUGH VERY EARLY ONSET INFLAMMATORY BOWEL DISEASE THAT DEVELOPS IN EARLY CHILDHOOD (BEFORE THE AGE OF 6 YEARS) HAS A DIFFERENT ETIOLOGY FROM CROHN'S DISEASE AND ULCERATIVE COLITIS, IT IS ALSO CHARACTERIZED BY CHRONIC INFLAMMATION OF THE GASTROINTESTINAL TRACT. BASICALLY, VERY EARLY ONSET INFLAMMATORY BOWEL DISEASE SHOULD BE CONSIDERED AS AN IMMUNODEFICIENCY WITH MONOGENIC ORIGIN WHERE BOTH GASTROINTESTINAL MANIFESTATIONS AND SYMPTOMS OF IMMUNODEFICIENCIES MAY DEVELOP IN VARIABLE COMBINATIONS. HOWEVER, IN THE FUTURE, THE EVALUATION OF GENETIC ALTERATIONS IN THE BACKGROUND OF THE DISEASE WILL PROBABLY BE PERFORMED BY NEXT-GENERATION SEQUENCING TECHNOLOGY; ONE SHOULD ALSO CONSIDER THAT THE SEQUENCE OF THE DNA STANDS IN CONTINUOUS INTERACTION WITH A WIDE VARIETY OF ENVIRONMENTAL EFFECTS, AMONG WHICH NUTRITION SHOULD BE EMPHASIZED BY ALL MEANS. EPIGENETIC ALTERATIONS THAT ARE INDUCED BY ENVIRONMENTAL FACTORS, COULD CONTRIBUTE TO THE PATHOGENESIS OF INFLAMMATORY BOWEL DISEASES THAT DEVELOP DURING CHILDHOOD, THEREFORE, THEY SHOULD ALSO BE IDENTIFIED DURING FURTHER RESEARCH. IT HAS A KEY SIGNIFICANCE TO ESTABLISH THE DIAGNOSIS OF VERY EARLY ONSET INFLAMMATORY BOWEL DISEASE AS EARLY AS POSSIBLE, BECAUSE THIS COULD GIVE THE OPPORTUNITY TO START THE ADEQUATE TREATMENT WHICH IS BONE MARROW TRANSPLANTATION IN THE CASE OF MONOGENIC IMMUNODEFICIENCIES. ORV HETIL. 2018; 159(49): 2050-2056. 2018 18 4844 23 ONE YEAR IN REVIEW 2019: PATHOGENESIS OF RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC INFLAMMATORY AUTOIMMUNE DISEASE INFLUENCED BY BOTH GENETIC AND ENVIRONMENTAL FACTORS. OVER THE LAST FEW YEARS, PARTICULAR ATTENTION HAS BEEN GIVEN TO NOVEL GENES AND TO THE CLOSE INTERACTION BETWEEN GENETIC FACTORS AND EPIGENETIC MECHANISMS. RESEARCH HAS ALSO FOCUSED ON THE INFLUENCE OF ENVIRONMENTAL FACTORS ON DISEASE DEVELOPMENT, AND ON NEW MECHANISMS OF THE INNATE AND ADAPTIVE IMMUNE SYSTEM THAT CAN INFLUENCE THE DIFFERENT STAGES OF RA. HOWEVER, THERE ARE STILL SEVERAL ASPECTS OF THE DISEASE THAT NEED FURTHER INVESTIGATION. SHEDDING SOME LIGHT ON THE DIFFERENT ASPECTS OF RA PATHOGENESIS WILL HELP TO IMPROVE THE CURRENT DIAGNOSTIC TOOLS AND TO IDENTIFY NEW TARGETS FOR THE DEVELOPMENT OF DISEASE-MODIFYING THERAPIES. THUS, IN THIS REVIEW WE SUMMARISE THE NEW INSIGHTS IN RA PATHOGENESIS, RESULTING FROM LITERATURE RESEARCH DATA PUBLISHED IN THE LAST YEAR. 2019 19 5670 25 SHARED (EPI)GENOMIC BACKGROUND CONNECTING NEURODEGENERATIVE DISEASES AND TYPE 2 DIABETES. THE PROGRESSIVE AGING OF POPULATIONS HAS RESULTED IN AN INCREASED PREVALENCE OF CHRONIC PATHOLOGIES, ESPECIALLY OF METABOLIC, NEURODEGENERATIVE AND MOVEMENT DISORDERS. IN PARTICULAR, TYPE 2 DIABETES (T2D), ALZHEIMER'S DISEASE (AD) AND PARKINSON'S DISEASE (PD) ARE AMONG THE MOST PREVALENT AGE-RELATED, MULTIFACTORIAL PATHOLOGIES THAT DESERVE PARTICULAR ATTENTION, GIVEN THEIR DRAMATIC IMPACT ON PATIENT QUALITY OF LIFE, THEIR ECONOMIC AND SOCIAL BURDEN AS WELL THE ETIOPATHOGENETIC MECHANISMS, WHICH MAY OVERLAP IN SOME CASES. INDEED, THE EXISTENCE OF COMMON TRIGGERING FACTORS REFLECTS THE CONTRIBUTION OF MUTUAL GENETIC, EPIGENETIC AND ENVIRONMENTAL FEATURES IN THE ETIOPATHOGENETIC MECHANISMS UNDERLYING T2D AND AD/PD. ON THIS SUBJECT, THIS REVIEW WILL SUMMARIZE THE SHARED (EPI)GENOMIC FEATURES THAT CHARACTERIZE THESE COMPLEX PATHOLOGIES. IN PARTICULAR, GENETIC VARIANTS AND GENE EXPRESSION PROFILES ASSOCIATED WITH T2D AND AD/PD WILL BE DISCUSSED AS POSSIBLE CONTRIBUTORS TO DETERMINE THE SUSCEPTIBILITY AND PROGRESSION TO THESE DISORDERS. MOREOVER, POTENTIAL SHARED EPIGENETIC MODIFICATIONS AND FACTORS AMONG T2D, AD AND PD WILL ALSO BE ILLUSTRATED. OVERALL, THIS REVIEW SHOWS THAT FINDINGS FROM GENOMIC STUDIES STILL DESERVES FURTHER RESEARCH TO EVALUATE AND IDENTIFY GENETIC FACTORS THAT DIRECTLY CONTRIBUTE TO THE SHARED ETIOPATHOGENESIS. MOREOVER, A COMMON EPIGENETIC BACKGROUND STILL NEEDS TO BE INVESTIGATED AND CHARACTERIZED. THE EVIDENCES DISCUSSED IN THIS REVIEW UNDERLINE THE IMPORTANCE OF INTEGRATING LARGE-SCALE (EPI)GENOMIC DATA WITH ADDITIONAL MOLECULAR INFORMATION AND CLINICAL AND SOCIAL BACKGROUND IN ORDER TO FINELY DISSECT THE COMPLEX ETIOPATHOGENIC NETWORKS THAT BUILD UP THE "DISEASE INTERACTOME" CHARACTERIZING T2D, AD AND PD. 2020 20 2404 18 EPIGENETIC RESEARCH IN MULTIPLE SCLEROSIS: PROGRESS, CHALLENGES, AND OPPORTUNITIES. MULTIPLE SCLEROSIS (MS) IS A CHRONIC INFLAMMATORY AND DEMYELINATING DISEASE OF THE CENTRAL NERVOUS SYSTEM. MS LIKELY RESULTS FROM A COMPLEX INTERPLAY BETWEEN PREDISPOSING CAUSAL GENE VARIANTS (THE STRONGEST INFLUENCE COMING FROM HLA CLASS II LOCUS) AND ENVIRONMENTAL RISK FACTORS SUCH AS SMOKING, INFECTIOUS MONONUCLEOSIS, AND LACK OF SUN EXPOSURE/VITAMIN D. HOWEVER, LITTLE IS KNOWN ABOUT THE MECHANISMS UNDERLYING MS DEVELOPMENT AND PROGRESSION. MOREOVER, THE CLINICAL HETEROGENEITY AND VARIABLE RESPONSE TO TREATMENT REPRESENT ADDITIONAL CHALLENGES TO A COMPREHENSIVE UNDERSTANDING AND EFFICIENT TREATMENT OF DISEASE. EPIGENETIC PROCESSES, SUCH AS DNA METHYLATION AND HISTONE POSTTRANSLATIONAL MODIFICATIONS, INTEGRATE INFLUENCES FROM THE GENES AND THE ENVIRONMENT TO REGULATE GENE EXPRESSION ACCORDINGLY. STUDYING EPIGENETIC MODIFICATIONS, WHICH ARE STABLE AND REVERSIBLE, MAY PROVIDE AN ALTERNATIVE APPROACH TO BETTER UNDERSTAND AND MANAGE DISEASE. WE HERE AIM TO REVIEW FINDINGS FROM EPIGENETIC STUDIES IN MS AND FURTHER DISCUSS THE CHALLENGES AND CLINICAL OPPORTUNITIES ARISING FROM EPIGENETIC RESEARCH, MANY OF WHICH APPLY TO OTHER DISEASES WITH SIMILAR COMPLEX ETIOLOGY. A GROWING BODY OF EVIDENCE SUPPORTS A ROLE OF EPIGENETIC PROCESSES IN THE MECHANISMS UNDERLYING IMMUNE PATHOGENESIS AND NERVOUS SYSTEM DYSFUNCTION IN MS. HOWEVER, DISPARITIES BETWEEN STUDIES SHED LIGHT ON THE NEED TO CONSIDER POSSIBLE CONFOUNDERS AND METHODOLOGICAL LIMITATIONS FOR A BETTER INTERPRETATION OF THE DATA. NEVERTHELESS, TRANSLATIONAL USE OF EPIGENETICS MIGHT OFFER NEW OPPORTUNITIES IN EPIGENETIC-BASED DIAGNOSTICS AND THERAPEUTIC TOOLS FOR A PERSONALIZED CARE OF MS PATIENTS. 2017